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dexar [7]
3 years ago
10

A customer works into a post office to purchase stamps. she purchases a total of 45 stamps. some of the stamps are 49cent stamps

and some are 33cents stamps. how many 49cent stamps and how many 33cent stamps did she purchase if the total cost of all the stamps was $17.89
Mathematics
1 answer:
baherus [9]3 years ago
5 0

Step-by-step explanation:Let number of 49 cents =A

                                             Let number of 33 cents=B

<u>A+B=45    equation 1</u>

1 $=100 cents

49 cents =.49 dollar

33 cents=.33 dollar

so .<u>49A+.33B=17.89    equation 2</u>

Add equation 1 and equation 2

since these are simultaneous equations

.49A+.33B=17.89

     A+     B=45

so divide equation 2 by 100 we get

49A+33B=1789

    A+B     =45 multiply equation 1 by 33 on both the sides we get

<u>33A+33B=1485     equation 3</u>

so subtract equation 3 from equation 2 we get

49A+33B=1789  equation 2

<u>33A+33B=1485    equation 3</u>

<u>16A+0      =304</u>

16A=304

A=304/16

A=19

putting nalue of A in equation 1 we get

A+B=45

19+B=45

B=45-19

B=26

so number of 49 cent stamps are 19

and number of 33 cent stamps are 26

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Use the two ordered pairs to find the slope, (m).

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Standard for<br> ola (y + 3)2 = -12(x - 2), iden<br> 1.<br> D<br> n111
Vedmedyk [2.9K]

Answer:

See below

Step-by-step explanation:

Your question is a bit unclear, so I'm going to assume you want the value of y or x:

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Suppose y varies inversely as x, and y=25 when x=3. Find x when y=15
malfutka [58]

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3 years ago
Three populations have proportions 0.1, 0.3, and 0.5. We select random samples of the size n from these populations. Only two of
IRINA_888 [86]

Answer:

(1) A Normal approximation to binomial can be applied for population 1, if <em>n</em> = 100.

(2) A Normal approximation to binomial can be applied for population 2, if <em>n</em> = 100, 50 and 40.

(3) A Normal approximation to binomial can be applied for population 2, if <em>n</em> = 100, 50, 40 and 20.

Step-by-step explanation:

Consider a random variable <em>X</em> following a Binomial distribution with parameters <em>n </em>and <em>p</em>.

If the sample selected is too large and the probability of success is close to 0.50 a Normal approximation to binomial can be applied to approximate the distribution of X if the following conditions are satisfied:

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Check the Normal approximation conditions for population 1, for all the provided <em>n</em> as follows:

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Thus, a Normal approximation to binomial can be applied for population 1, if <em>n</em> = 100.

(2)

Check the Normal approximation conditions for population 2, for all the provided <em>n</em> as follows:

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Thus, a Normal approximation to binomial can be applied for population 2, if <em>n</em> = 100, 50 and 40.

(3)

Check the Normal approximation conditions for population 3, for all the provided <em>n</em> as follows:

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Thus, a Normal approximation to binomial can be applied for population 2, if <em>n</em> = 100, 50, 40 and 20.

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